Fatto generale: 61 is the code for international direct dial phone calls to Australia.
Fatto matematico: 61 is the sum of two squares, 52 + 62, and it is also a centered square number, a centered hexagonal number and a centered decagonal number.
Trivia: 61 is the number of points required to win a "standard" game of Cribbage.
Data storica: March 1st is the day in 1867 that Nebraska becomes the 37th U.S. state; Lancaster, Nebraska is renamed Lincoln and becomes the state capital.